A high-salt diet has long been linked to higher odds of developing
high blood pressure and heart disease as well as an increased risk
of heart attack, stroke and heart failure. But determining the ideal
amount of dietary salt is controversial because some research has
also found an elevated risk of heart disease, high blood pressure
and heart attacks in otherwise healthy people who consume too little
In the current study, half of the people consumed at least 3.73
grams a day of sodium, the equivalent of about two teaspoons of
Compared with adults who ate less sodium, people who consumed more
than 3.7 grams of sodium a day were more likely to have enlargement
in the left chambers of the heart that are responsible for pumping
oxygen-rich blood into the body. They were also more likely to have
signs of muscle strain in the heart that can precede structural
“This study enhances our understanding of the adverse effects of
salt intake on heart function,” said lead study author Dr. Senthil
Selvaraj, a researcher at the Hospital of the University of
Pennsylvania in Philadelphia.
While the results don’t settle the debate over the optimal amount of
salt, the findings should still encourage people who eat a lot of
salt to cut back, Selvaraj said by email. That’s because reducing
sodium intake can help reverse high blood pressure, a major risk
factor for heart failure, stroke and heart attacks.
“There is still a healthy debate ongoing,” Selvaraj added. “It is
still worth the effort to reduce your sodium intake.”
Cardiovascular diseases are the leading cause of death worldwide,
killing almost one in every three people.
Sodium is found not only in table salt, but also in a variety of
foods such as bread, milk, eggs, meat, and shellfish as well as
processed items like soup, pretzels, popcorn, soy sauce and bouillon
or stock cubes.
To lower the risk of heart disease, adults should reduce sodium
intake to less than 2 grams a day, or the equivalent of about one
teaspoon of salt, according to the World Health Organization (WHO).
For the current study, researchers examined data from lab tests of
sodium intake, heart structure and heart function for almost 3,000
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Participants were 49 years old on average, 54 percent had high blood
pressure and half were African-American. They were typically
overweight or obese.
To assess how sodium intake influenced the heart, researchers
accounted for age, sex, smoking status, alcohol use, activity
levels, and certain medications.
The study wasn’t a controlled experiment designed to prove how or if
salt damages the heart or impairs heart function.
One limitation of the study is that researchers tested sodium intake
using overnight urine samples, which may not be as accurate as the
gold standard, 24-hour urine collection, the authors note in the
Journal of the American College of Cardiology.
Researchers also didn’t have enough data on people who consumed very
little sodium to assess how low salt intake influences the heart.
“We know less than we should about salt,” said Thomas Marwick,
author of an accompanying editorial and director of the Baker Heart
and Diabetes Institute in Melbourne, Australia.
“In general, most of the population take far more salt than is good
for them and this is a reminder to reduce intake,” Marwick said by
“It’s ubiquitous and hard to reduce to very low levels,” Marwick
added. “While some zealots want to reduce intake to zero, I’m not
sure that drastic reduction is necessarily beneficial.”
SOURCE: http://bit.ly/2wlZgK5 Journal of the American College of
Cardiology, online July 31, 2017.
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